﻿#include <iostream>
#include <vector>
#include <queue>
using namespace std;

class Solution
{
    size_t m, n;
    int dx[4] = { 0,0,1,-1 };
    int dy[4] = { 1,-1,0,0 };
    bool vis[510][510];
public:
    // 1020. 飞地的数量
    int numEnclaves(vector<vector<int>>& grid)
    {
        m = grid.size(), n = grid[0].size();
        queue<pair<int, int>> q;
        for (int i = 0; i < m; i++)
            for (int j = 0; j < n; j++)
                if (i == 0 || j == 0 || i == m - 1 || j == n - 1)
                    if (grid[i][j] == 1)
                    {
                        q.push({ i,j });
                        vis[i][j] = true;
                    }

        while (q.size())
        {
            pair<int, int> p = q.front();
            q.pop();
            int a = p.first, b = p.second;
            for (int k = 0; k < 4; k++)
            {
                int x = a + dx[k], y = b + dy[k];
                if (x >= 0 && x < m && y >= 0 && y < n && !vis[x][y] && grid[x][y]==1)
                {
                    q.push({ x,y });
                    vis[x][y] = true;
                }
            }
        }

        int ret = 0;
        for (int i = 0; i < m; i++)
            for (int j = 0; j < n; j++)
                if (grid[i][j] == 1 && !vis[i][j])
                    ret++;
        return ret;
    }

    // 1765. 地图中的最高点
    vector<vector<int>> highestPeak(vector<vector<int>>& isWater)
    {
        m = isWater.size(), n = isWater[0].size();
        vector<vector<int>> dist(m, vector<int>(n, -1));
        queue<pair<int, int>> q;

        for (int i = 0; i < m; i++)
            for (int j = 0; j < n; j++)
                if (isWater[i][j])
                {
                    q.push({ i,j });
                    dist[i][j] = 0;
                }

        while (q.size())
        {
            pair<int, int> p = q.front();
            q.pop();
            int a = p.first, b = p.second;

            for (int k = 0; k < 4; k++)
            {
                int x = a + dx[k], y = b + dy[k];
                if (x >= 0 && x < m && y >= 0 && y < n && dist[x][y] == -1)
                {
                    dist[x][y] = dist[a][b] + 1;
                    q.push({ x,y });
                }
            }
        }
        return dist;
    }
};

int main()
{
    vector<vector<int>> v{ {0,0,0,0},{1,0,1,0},{0,1,1,0},{0,0,0,0} };
    Solution().numEnclaves(v);

    return 0;
}